1. Field of Invention
The present invention relates generally to data communication systems. More particularly, the present invention relates to systems and methods for managing limited network capacity, as well as to systems and methods for handling data traffic having different types of content.
2. Description of the Related Art
The demand for data communication services is growing at an explosive rate. Much of the increased demand is due to the fact that more residential and business computer users are becoming connected to the Internet. Furthermore, the types of traffic being carried by the Internet are shifting from lower bandwidth applications towards high bandwidth applications which include voice traffic and video traffic.
To accommodate the growth and demand for Internet services, service providers are rapidly installing network switching devices, such as routers, and upgrading physical media throughout their networks. For user access, dial-in lines are being replaced by digital subscriber loop (DSL), cable modem, and broadband fixed wireless. Increasingly, the network backbone exploits optical fiber physical media. Fiber is also being deployed further toward the network edge so that, for example, data over cable networks are being transformed into hybrid fiber cable (HFC) networks. However, even with these advances in data networking technologies and the high level of investment by service providers, demand for network bandwidth continues to outpace supply.
One technique that may be applied to expand the effective throughput of a network is data compression. Data compression techniques generally take advantage of redundancy inherent in many types of data. For example, text documents may be compressed by assigning a variable number of bits to individual letters depending on their frequency in the document. When letters that appear frequently in a document are encoded by a very small number of bits, the overall amount of data required to store and/or communicate the document may be greatly reduced. More sophisticated techniques may also be used to encode voice and/or video traffic.
The processing necessary to perform compression at a data source and decompression at the data destination, i.e., a data sink, often adds what may be considered to be an intolerable level of delay. This delay may be relatively insignificant for certain types of data traffic such as electronic mail, or e-mail, traffic, since e-mail is generally not read in real time. For web downloading, the delay caused by compression and decompression may be tolerable but undesirable. In general, relatively long delays caused by compression and decompression are considered to be intolerable for real time voice or video communications. As a result, minimizing the need for data compression effectively serves to minimize the time needed to transfer data traffic across a network.
Some types of data traffic are generally easier to compress than others. By way of example, it may be easier, as well as faster, to compress packets which contain text-based data than to compress packets which contain GIF-based data, even though a delay in the transmission of text-based data may be less tolerable than a delay in the transmission of GIF-based data. In some cases, it may be that slightly delaying the transmission of text-based data by compressing the text-based data is preferable to greatly delaying the transmission of GIF-based data by compressing the GIF-based data.
Therefore, what is needed are systems and methods for data communication that take advantage of the capacity increasing capabilities of data compression technology, while balancing the compression of delay sensitive traffic, e.g., high priority traffic, against the compression of traffic which is less delay sensitive but more difficult to compress in order to substantially minimize the adverse consequences of compression processing calculations.